<!DOCTYPE HTML>
<html>
<body>
<canvas id="myCanvas" width="200" height="200" style="border:2px solid blue;">
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</canvas>
<script type="text/javascript">
  let canvas = document.getElementById('myCanvas')
  let ctx = canvas.getContext('2d')
  ctx.beginPath()
  ctx.arc(75, 75, 50, Math.PI / 180 * -90, Math.PI / 180 * 90)
  ctx.lineWidth = 10
  ctx.strokeStyle = 'green'
  ctx.stroke()
  ctx.closePath()
</script>
</body>
</html>
